This page from GCHQ’s internal GCWiki, last updated on 1 May 2012 documents progress in a variety of the agency’ projects: see Facing Data Deluge, Secret U.K. Spying Report Warned of Intelligence Failure, 7 June 2016.

This extract from a 2012 GCHQ document details progress in the operation against Belgian telecommunications company Belgacom in the first quarter of 2012: see the Intercept article Operation Socialist: The Inside Story of How British Spies Hacked Belgium’s Largest Telco, 13 December 2014.

﻿CNE Access to BELGACOM GRX Operator: (GREEN) This work continues to be
very productive with the CNE EREPO team providing new requirements for the NAC
to help steer and support their operation.

This GCHQ presentation from 2011 provides the background to the agency’s hacking attack on Belgacom: see the Intercept article Operation Socialist: The Inside Story of How British Spies Hacked Belgium’s Largest Telco, 13 December 2014. gchq-mobile-networks-in-my-noc-world

﻿TOP SECRET STRAP 2
Mobile Networks in
World
Head of GCHQ NAC
n/\c
This information is exempt from disclosure under the Freedom of Information Act 2000 and may be subject to exemptio...

These intenal NSA minutes from a meeting that took place on 8 June 2009 discuss GCSB activities and interoperability between NSA systems: see the New Zealand Herald article NZ’s spy reach stretches across globe, 11 March 2015.